Water and seltzer provide nearly identical hydration benefits, according to the beverage hydration index developed by researchers. While both options effectively maintain fluid balance in the body, they differ primarily in their carbonation content, which can cause gastrointestinal side effects for some individuals.
How Does Sparkling Water Compare to Still Water for Hydration?
Research indicates that sparkling water and still water are equally effective at hydrating the body. The beverage hydration index, a tool created through a randomized trial of 72 men, established that water and seltzer are equally hydrating when consumed in an adequately hydrated state. Because sparkling water is simply water infused with carbon dioxide, it lacks the caloric or macronutrient density found in other beverages.
Why Does Carbonation Cause Bloating?
While sparkling water is generally well-tolerated, the added carbon dioxide can lead to physical discomfort. According to Hill, a common side effect of carbonation is bloating or gas. This occurs because the air it adds to your gut may cause discomfort. These effects are typically harmless, but they may be uncomfortable.
What Are the Nutritional Differences?
From a nutritional standpoint, the differences between these beverages are negligible. Data from the University of Rochester Medical Center notes that municipal water may contain tiny amounts of minerals like calcium and magnesium. Similarly, sparkling water is pretty much identical nutritionally to still water, as it has almost zero nutritional value.
However, consumers should exercise caution when selecting commercial brands. Destini Moody, a nutritionist at Live It Up Nutrition, notes that while plain sparkling water does not tend to have micronutrients, antioxidants, or other health-promoting compounds, it can help improve hydration status. Some products may contain added sodium, fruit juice, or puree, or sugar or artificial sweeteners, which alter the nutritional profile of the drink. Checking the ingredient list is necessary to determine exactly what you’re getting.
Quick Comparison: Still vs. Sparkling Water
| Feature | Still Water | Sparkling Water |
| :— | :— | :— |
| Hydration Efficiency | High | High |
| Carbonation | None | Yes |
| Common Side Effects | None | Potential bloating/gas |
| Typical Calories | 0 | 0 (unless flavored) |
Key Takeaways for Daily Hydration
* Equivalency: Both water and seltzer are effective for maintaining hydration status and supporting energy levels.
* Ingredient Awareness: Always verify the label for added sugars, fruit purees, or artificial sweeteners in flavored sparkling waters.
* Individual Tolerance: If carbonated water causes digestive discomfort, sticking to plain water is a way to avoid bloating.
* Nutritional Value: Neither beverage serves as a source of essential micronutrients or antioxidants.